Bug#21557 entries in the general query log truncated at 1000 characters.

The general log write function (general_log_print) uses printf style
arguments which need to be pre-processed, meaning that the all arguments
are copied to a single buffer and the problem is that the buffer size is
constant (1022 characters) but queries can be much larger then this.

The solution is to introduce a new log write function that accepts a
buffer and it's length as arguments. The function is to be used when
a formatted output is not required, which is the case for almost all
query write-to-log calls.

This is a incompatible change with respect to the log format of prepared
statements.


mysql-test/r/log_tables.result:
  Add test case result for Bug#21557
mysql-test/t/log_tables.test:
  Add test case for Bug#21557
sql/log.cc:
  Introduce the logger function general_log_write which is similar to
  general_log_print but accepts a single buffer and the buffer length.
  The function doesn't perform any formatting and sends the buffer
  directly to the underlying log handlers.
sql/log.h:
  Introduce the logger function general_log_write.
sql/log_event.cc:
  Pass the query buffer directly to the logger function, formatting
  is not required on this case.
sql/mysql_priv.h:
  Prototype for the logger function general_log_write.
sql/sp_head.cc:
  Pass the query buffer directly to the logger function, formatting
  is not required on this case.
sql/sql_parse.cc:
  Pass the buffer directly to the logger function when formatting
  is not required.
sql/sql_prepare.cc:
  Don't log the statement id, it avoids making a extra copy of the query
  and the query is not truncated anymore if it exceeds the limit.

mysql-test/t/log_tables.test

@@ -807,3 +807,119 @@ DROP DATABASE IF EXISTS `db_17876`;
 SET GLOBAL general_log = @old_general_log_state;
 SET GLOBAL slow_query_log = @old_slow_log_state;
 
+#
+# Bug#21557 entries in the general query log truncated at 1000 characters.
+#
+
+truncate table mysql.general_log;
+set @old_general_log_state = @@global.general_log;
+set global general_log = on;
+--disable_result_log
+set @lparam = "000 001 002 003 004 005 006 007 008 009"
+              "010 011 012 013 014 015 016 017 018 019"
+              "020 021 022 023 024 025 026 027 028 029"
+              "030 031 032 033 034 035 036 037 038 039"
+              "040 041 042 043 044 045 046 047 048 049"
+              "050 051 052 053 054 055 056 057 058 059"
+              "060 061 062 063 064 065 066 067 068 069"
+              "070 071 072 073 074 075 076 077 078 079"
+              "080 081 082 083 084 085 086 087 088 089"
+              "090 091 092 093 094 095 096 097 098 099"
+              "100 101 102 103 104 105 106 107 108 109"
+              "110 111 112 113 114 115 116 117 118 119"
+              "120 121 122 123 124 125 126 127 128 129"
+              "130 131 132 133 134 135 136 137 138 139"
+              "140 141 142 143 144 145 146 147 148 149"
+              "150 151 152 153 154 155 156 157 158 159"
+              "160 161 162 163 164 165 166 167 168 169"
+              "170 171 172 173 174 175 176 177 178 179"
+              "180 181 182 183 184 185 186 187 188 189"
+              "190 191 192 193 194 195 196 197 198 199"
+              "200 201 202 203 204 205 206 207 208 209"
+              "210 211 212 213 214 215 216 217 218 219"
+              "220 221 222 223 224 225 226 227 228 229"
+              "230 231 232 233 234 235 236 237 238 239"
+              "240 241 242 243 244 245 246 247 248 249"
+              "250 251 252 253 254 255 256 257 258 259"
+              "260 261 262 263 264 265 266 267 268 269"
+              "270 271 272 273 274 275 276 277 278 279"
+              "280 281 282 283 284 285 286 287 288 289"
+              "290 291 292 293 294 295 296 297 298 299"
+              "300 301 302 303 304 305 306 307 308 309"
+              "310 311 312 313 314 315 316 317 318 319"
+              "320 321 322 323 324 325 326 327 328 329"
+              "330 331 332 333 334 335 336 337 338 339"
+              "340 341 342 343 344 345 346 347 348 349"
+              "350 351 352 353 354 355 356 357 358 359"
+              "360 361 362 363 364 365 366 367 368 369"
+              "370 371 372 373 374 375 376 377 378 379"
+              "380 381 382 383 384 385 386 387 388 389"
+              "390 391 392 393 394 395 396 397 398 399"
+              "400 401 402 403 404 405 406 407 408 409"
+              "410 411 412 413 414 415 416 417 418 419"
+              "420 421 422 423 424 425 426 427 428 429"
+              "430 431 432 433 434 435 436 437 438 439"
+              "440 441 442 443 444 445 446 447 448 449"
+              "450 451 452 453 454 455 456 457 458 459"
+              "460 461 462 463 464 465 466 467 468 469"
+              "470 471 472 473 474 475 476 477 478 479"
+              "480 481 482 483 484 485 486 487 488 489"
+              "490 491 492 493 494 495 496 497 498 499"
+              "500 501 502 503 504 505 506 507 508 509"
+              "510 511 512 513 514 515 516 517 518 519"
+              "520 521 522 523 524 525 526 527 528 529"
+              "530 531 532 533 534 535 536 537 538 539"
+              "540 541 542 543 544 545 546 547 548 549"
+              "550 551 552 553 554 555 556 557 558 559"
+              "560 561 562 563 564 565 566 567 568 569"
+              "570 571 572 573 574 575 576 577 578 579"
+              "580 581 582 583 584 585 586 587 588 589"
+              "590 591 592 593 594 595 596 597 598 599"
+              "600 601 602 603 604 605 606 607 608 609"
+              "610 611 612 613 614 615 616 617 618 619"
+              "620 621 622 623 624 625 626 627 628 629"
+              "630 631 632 633 634 635 636 637 638 639"
+              "640 641 642 643 644 645 646 647 648 649"
+              "650 651 652 653 654 655 656 657 658 659"
+              "660 661 662 663 664 665 666 667 668 669"
+              "670 671 672 673 674 675 676 677 678 679"
+              "680 681 682 683 684 685 686 687 688 689"
+              "690 691 692 693 694 695 696 697 698 699"
+              "700 701 702 703 704 705 706 707 708 709"
+              "710 711 712 713 714 715 716 717 718 719"
+              "720 721 722 723 724 725 726 727 728 729"
+              "730 731 732 733 734 735 736 737 738 739"
+              "740 741 742 743 744 745 746 747 748 749"
+              "750 751 752 753 754 755 756 757 758 759"
+              "760 761 762 763 764 765 766 767 768 769"
+              "770 771 772 773 774 775 776 777 778 779"
+              "780 781 782 783 784 785 786 787 788 789"
+              "790 791 792 793 794 795 796 797 798 799"
+              "800 801 802 803 804 805 806 807 808 809"
+              "810 811 812 813 814 815 816 817 818 819"
+              "820 821 822 823 824 825 826 827 828 829"
+              "830 831 832 833 834 835 836 837 838 839"
+              "840 841 842 843 844 845 846 847 848 849"
+              "850 851 852 853 854 855 856 857 858 859"
+              "860 861 862 863 864 865 866 867 868 869"
+              "870 871 872 873 874 875 876 877 878 879"
+              "880 881 882 883 884 885 886 887 888 889"
+              "890 891 892 893 894 895 896 897 898 899"
+              "900 901 902 903 904 905 906 907 908 909"
+              "910 911 912 913 914 915 916 917 918 919"
+              "920 921 922 923 924 925 926 927 928 929"
+              "930 931 932 933 934 935 936 937 938 939"
+              "940 941 942 943 944 945 946 947 948 949"
+              "950 951 952 953 954 955 956 957 958 959"
+              "960 961 962 963 964 965 966 967 968 969"
+              "970 971 972 973 974 975 976 977 978 979"
+              "980 981 982 983 984 985 986 987 988 989"
+              "990 991 992 993 994 995 996 997 998 999";
+--enable_result_log
+prepare long_query from "select ? as long_query";
+--disable_result_log
+execute long_query using @lparam;
+--enable_result_log
+select command_type, argument from mysql.general_log;
+deallocate prepare long_query;
+set global general_log = @old_general_log_state;

sql/log.cc

@@ -944,73 +944,65 @@ bool LOGGER::slow_log_print(THD *thd, const char *query, uint query_length,
   return error;
 }
 
-bool LOGGER::general_log_print(THD *thd, enum enum_server_command command,
-                               const char *format, va_list args)
+bool LOGGER::general_log_write(THD *thd, enum enum_server_command command,
+                               const char *query, uint query_length)
 {
   bool error= FALSE;
   Log_event_handler **current_handler= general_log_handler_list;
+  char user_host_buff[MAX_USER_HOST_SIZE];
+  Security_context *sctx= thd->security_ctx;
+  ulong id;
+  uint user_host_len= 0;
+  time_t current_time;
 
-  /*
-    Print the message to the buffer if we have at least one log event handler
-    enabled and want to log this king of commands
-  */
-  if (*general_log_handler_list && (what_to_log & (1L << (uint) command)))
-  {
-    char message_buff[MAX_LOG_BUFFER_SIZE];
-    char user_host_buff[MAX_USER_HOST_SIZE];
-    Security_context *sctx= thd->security_ctx;
-    ulong id;
-    uint message_buff_len= 0, user_host_len= 0;
-    time_t current_time;
-    if (thd)
-    {                                           /* Normal thread */
-      if ((thd->options & OPTION_LOG_OFF)
-#ifndef NO_EMBEDDED_ACCESS_CHECKS
-          && (sctx->master_access & SUPER_ACL)
-#endif
-         )
-      {
-        return 0;                         /* No logging */
-      }
-      id= thd->thread_id;
-    }
-    else
-      id=0;                                     /* Log from connect handler */
+  if (thd)
+    id= thd->thread_id;                 /* Normal thread */
+  else
+    id= 0;                              /* Log from connect handler */
 
-    lock_shared();
-    if (!opt_log)
-    {
-      unlock();
-      return 0;
-    }
-    user_host_len= strxnmov(user_host_buff, MAX_USER_HOST_SIZE,
-                            sctx->priv_user ? sctx->priv_user : "", "[",
-                            sctx->user ? sctx->user : "", "] @ ",
-                            sctx->host ? sctx->host : "", " [",
-                            sctx->ip ? sctx->ip : "", "]", NullS) -
-                                                            user_host_buff;
-
-    /* prepare message */
-    if (format)
-      message_buff_len= my_vsnprintf(message_buff,
-                   sizeof(message_buff), format, args);
-    else
-      message_buff[0]= '\0';
-
-    current_time= my_time(0);
-    while (*current_handler)
-      error+= (*current_handler++)->
-        log_general(thd, current_time, user_host_buff,
-                   user_host_len, id,
-                   command_name[(uint) command].str,
-                   command_name[(uint) command].length,
-                   message_buff, message_buff_len,
-                   thd->variables.character_set_client) || error;
+  lock_shared();
+  if (!opt_log)
+  {
     unlock();
+    return 0;
   }
+  user_host_len= strxnmov(user_host_buff, MAX_USER_HOST_SIZE,
+                          sctx->priv_user ? sctx->priv_user : "", "[",
+                          sctx->user ? sctx->user : "", "] @ ",
+                          sctx->host ? sctx->host : "", " [",
+                          sctx->ip ? sctx->ip : "", "]", NullS) -
+                                                          user_host_buff;
+
+  current_time= my_time(0);
+  while (*current_handler)
+    error+= (*current_handler++)->
+      log_general(thd, current_time, user_host_buff,
+                  user_host_len, id,
+                  command_name[(uint) command].str,
+                  command_name[(uint) command].length,
+                  query, query_length,
+                  thd->variables.character_set_client) || error;
+  unlock();
+
   return error;
 }
 
+bool LOGGER::general_log_print(THD *thd, enum enum_server_command command,
+                               const char *format, va_list args)
+{
+  uint message_buff_len= 0;
+  char message_buff[MAX_LOG_BUFFER_SIZE];
+
+  /* prepare message */
+  if (format)
+    message_buff_len= my_vsnprintf(message_buff, sizeof(message_buff),
+                                   format, args);
+  else
+    message_buff[0]= '\0';
+
+  return general_log_write(thd, command, message_buff, message_buff_len);
+}
+
 void LOGGER::init_error_log(uint error_log_printer)
 {
   if (error_log_printer & LOG_NONE)
@@ -2075,10 +2067,10 @@ bool MYSQL_QUERY_LOG::write(THD *thd, time_t current_time,
         if (my_b_write(&log_file, (uchar*) buff, buff_len))
           tmp_errno= errno;
       }
-      if (my_b_printf(&log_file, "# User@Host: ", sizeof("# User@Host: ") - 1)
-          != sizeof("# User@Host: ") - 1)
+      const uchar uh[]= "# User@Host: ";
+      if (my_b_write(&log_file, uh, sizeof(uh) - 1))
         tmp_errno= errno;
-      if (my_b_printf(&log_file, user_host, user_host_len) != user_host_len)
+      if (my_b_write(&log_file, (uchar*) user_host, user_host_len))
         tmp_errno= errno;
       if (my_b_write(&log_file, (uchar*) "\n", 1))
         tmp_errno= errno;
@@ -3736,12 +3728,44 @@ bool slow_log_print(THD *thd, const char *query, uint query_length,
 }
 
 
+bool LOGGER::log_command(THD *thd, enum enum_server_command command)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  Security_context *sctx= thd->security_ctx;
+#endif
+  /*
+    Log command if we have at least one log event handler enabled and want
+    to log this king of commands
+  */
+  if (*general_log_handler_list && (what_to_log & (1L << (uint) command)))
+  {
+    if ((thd->options & OPTION_LOG_OFF)
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+         && (sctx->master_access & SUPER_ACL)
+#endif
+       )
+    {
+      /* No logging */
+      return FALSE;
+    }
+
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+
 bool general_log_print(THD *thd, enum enum_server_command command,
                        const char *format, ...)
 {
   va_list args;
   uint error= 0;
 
+  /* Print the message to the buffer if we want to log this king of commands */
+  if (! logger.log_command(thd, command))
+    return FALSE;
+
   va_start(args, format);
   error= logger.general_log_print(thd, command, format, args);
   va_end(args);
@@ -3749,6 +3773,16 @@ bool general_log_print(THD *thd, enum enum_server_command command,
   return error;
 }
 
+bool general_log_write(THD *thd, enum enum_server_command command,
+                       const char *query, uint query_length)
+{
+  /* Write the message to the log if we want to log this king of commands */
+  if (logger.log_command(thd, command))
+    return logger.general_log_write(thd, command, query, query_length);
+
+  return FALSE;
+}
+
 void MYSQL_BIN_LOG::rotate_and_purge(uint flags)
 {
   if (!(flags & RP_LOCK_LOG_IS_ALREADY_LOCKED))

sql/log.h

@@ -499,6 +499,8 @@ class LOGGER
   void lock_exclusive() { rw_wrlock(&LOCK_logger); }
   void unlock() { rw_unlock(&LOCK_logger); }
   bool is_log_table_enabled(uint log_table_type);
+  bool log_command(THD *thd, enum enum_server_command command);
+
   /*
     We want to initialize all log mutexes as soon as possible,
     but we cannot do it in constructor, as safe_mutex relies on
@@ -518,6 +520,8 @@ class LOGGER
                       ulonglong current_utime);
   bool general_log_print(THD *thd,enum enum_server_command command,
                          const char *format, va_list args);
+  bool general_log_write(THD *thd, enum enum_server_command command,
+                         const char *query, uint query_length);
 
   /* we use this function to setup all enabled log event handlers */
   int set_handlers(uint error_log_printer,

sql/log_event.cc

@@ -2113,7 +2113,7 @@ START SLAVE; . Query: '%s'", expected_error, thd->query);
 
     /* If the query was not ignored, it is printed to the general log */
     if (thd->net.last_errno != ER_SLAVE_IGNORED_TABLE)
-      general_log_print(thd, COM_QUERY, "%s", thd->query);
+      general_log_write(thd, COM_QUERY, thd->query, thd->query_length);
 
 compare_errors:
 

sql/mysql_priv.h

@@ -740,6 +740,9 @@ bool slow_log_print(THD *thd, const char *query, uint query_length,
 bool general_log_print(THD *thd, enum enum_server_command command,
                        const char *format,...);
 
+bool general_log_write(THD *thd, enum enum_server_command command,
+                       const char *query, uint query_length);
+
 #include "sql_class.h"
 #include "sql_acl.h"
 #include "tztime.h"

sql/sp_head.cc

@@ -2707,7 +2707,7 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
       queries with SP vars can't be cached)
     */
     if (unlikely((thd->options & OPTION_LOG_OFF)==0))
-      general_log_print(thd, COM_QUERY, "%s", thd->query);
+      general_log_write(thd, COM_QUERY, thd->query, thd->query_length);
 
     if (query_cache_send_result_to_client(thd,
 					  thd->query, thd->query_length) <= 0)

sql/sql_parse.cc

@@ -782,7 +782,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
 			packet, packet_length, thd->charset());
     if (!mysql_change_db(thd, &tmp, FALSE))
     {
-      general_log_print(thd, command, "%s",thd->db);
+      general_log_write(thd, command, thd->db, thd->db_length);
       send_ok(thd);
     }
     break;
@@ -980,10 +980,9 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       break;					// fatal error is set
     char *packet_end= thd->query + thd->query_length;
     /* 'b' stands for 'buffer' parameter', special for 'my_snprintf' */
-    const char *format= "%.*b";
     const char* found_semicolon= NULL;
 
-    general_log_print(thd, command, format, thd->query_length, thd->query);
+    general_log_write(thd, command, thd->query, thd->query_length);
     DBUG_PRINT("query",("%-.4096s",thd->query));
 
     if (!(specialflag & SPECIAL_NO_PRIOR))
@@ -1142,7 +1141,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
                    ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
 	break;
       }
-      general_log_print(thd, command, db.str);
+      general_log_write(thd, command, db.str, db.length);
       mysql_rm_db(thd, db.str, 0, 0);
       break;
     }

sql/sql_prepare.cc

@@ -2947,12 +2947,7 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len)
       the general log.
     */
     if (thd->spcont == NULL)
-    {
-      const char *format= "[%lu] %.*b";
-      general_log_print(thd, COM_STMT_PREPARE, format, id,
-                        query_length, query);
-
-    }
+      general_log_write(thd, COM_STMT_PREPARE, query, query_length);
   }
   DBUG_RETURN(error);
 }
@@ -3150,11 +3145,7 @@ bool Prepared_statement::execute(String *expanded_query, bool open_cursor)
     the general log.
   */
   if (error == 0 && thd->spcont == NULL)
-  {
-    const char *format= "[%lu] %.*b";
-    general_log_print(thd, COM_STMT_EXECUTE, format, id,
-                      thd->query_length, thd->query);
-  }
+    general_log_write(thd, COM_STMT_EXECUTE, thd->query, thd->query_length);
 
 error:
   flags&= ~ (uint) IS_IN_USE;